<?\x0d function x($a,$b){return str_repeat($a,$b);}\x0d while($n=fgets(STDIN)){echo x(" ",$n).x("_",$n*2)."\n";for($j=0;$j<$n;$j++)printf("%s/%s/%s\\\n",x(" ",$n-$j-1),x($j==$n-1?"_":" ",$n*2-1),x(" ",$j*2));for($j=0;$j<$n;$j++)printf("%s\\%s\\%s/\n",x(" ",$j),x($j==$n-1?"_":" ",$n*2-1),x(" ",($n-$j-1)*2));}
Note that non-ascii characters in the above source code will be escaped (such as \x9f).